Improvement of Three-phase Voltage Unbalance Characteristics Due to U-V/V-V Connections of Transformers Using a D-STATCOM

• Main Authors: Wei-ShengLiu, 劉威盛
• Other Authors: Li Wang
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/27641960399058856500

碩士 === 國立成功大學 === 電機工程學系 === 104 === The U-V or V-V winding connection of two single-phase distribution transformers is widely used in most utility companies including Taiwan Power Company (TPC) to deliver power to various three-phase loads. Such special winding connection can cause three-phase voltage unbalance which leads to the trip of ground relay, extra power loss on distribution lines, and reduced efficiency of induction motors. This thesis proposes a distributed static synchronous compensator (D-STATCOM) to decrease the voltage unbalance due to U-V or V-V winding connection of distribution transformers. System configuration 1 is based on the IEEE 4-node test feeder with U-V or V-V winding connection of transformers while the D-STATCOM is proposed to reduce three-phase voltage unbalance. System configuration 2 is based on a distribution system of TPC while the location of the D-STATCOM and the modification of U-V/V-V winding connection of transformers are carried out. The simulation results show that the use of the proposed D-STATCOM to reduce three-phase voltage unbalance due to U-V or V-V winding connection of distribution transformers is feasible.